1. Field of the Invention
The present invention relates generally to approximating apparatus for surgical instrumentation and more particularly to apparatus which effects substantially parallel approximation of the jaw structure for surgical instrumentation.
2. Description of the Related Art
A wide variety of surgical procedures used today involve surgical instrumentation having jaw structure such as, for example, grippers, graspers, dissectors, clamps, cutting elements, stapling elements and tissue measuring devices. In each of these types of jaw structure affected tissue is captured by the jaws for manipulation. The ease and accuracy of this tissue capturing step is extremely important if the surgical procedure is to be carried out in an efficient manner. One type of jaw structure currently used captures tissue by a pivotal action of the jaw structure wherein the jaws close progressively from a pivot point outward to the end of the jaw structure. See, for example U.S. Pat. Nos. 3,866,610; 4,243,047; 4,369,788; 4,512,343; 4,572,185; 4,590,936 and 4,674,501. This pivotal action can, in certain circumstances, overcompress captured tissue nearest to the pivot point while undercompressing captured tissue near the ends of the jaw structure. The uneven compression can result in uneven cutting, unintentional tissue trauma, and/or inaccurate tissue measurement or joining. This is particularly true in endoscopic or laparoscopic procedures where accessibility is extremely limited. In these procedures accuracy and precision are vitally important. Apparatus must be capable of easily and accurately capturing tissue for subsequent manipulation without unintentional trauma.
A more accurate and atraumatic way of approximating surgical jaw structure is by parallel approximation. This approach has been utilized with some success in the area of surgical clamping. For example, in Cooper U.S. Pat. No. 4,931,058 and Blasnik et al. U.S. Pat. No. 4,976,721 surgical clamp structure is shown wherein spring loaded parallel clamping jaws are moved together in parallel orientation by compression of locking structure disposed on an end of the jaw structure. These surgical clamps however are not readily operable in remote or limited visibility applications such as, for example, endoscopic or laparoscopic procedures and do not make use of camming action.
Similarly, some surgical stapler designs make use of parallel approximation to facilitate capture and joining of tissue. For example, U.S. Pat. Nos. 3,269,630; 3,795,034; 4,319,576; 4,442,964; 4,603,693; 4,788,978 and 4,930,503 disclose some degree of parallel approximation of anvils and staple cartridge elements. However, these designs are somewhat bulky and in some cases difficult to manipulate. U.S. Pat. No. 3,844,289 shows a scissors type hemostat having L-shaped jaw structure for capturing tissue therebetween. A clip applier is attached to the hemostat for clipping the captured tissue. In operation, the clip applier moves substantially perpendicular to the plane of the working ends of the hemostat jaw structure by means of pins and slots to clip the captured tissue. None of these references utilize camming structure or a camming action to effect substantially parallel approximation of surgical jaw structure while maintaining an efficient and simple mode of operation for the working ends thereof.
Therefore, it would be highly desirable to have approximating jaw structure for surgical instrumentation which allows for accurate and precise substantially parallel approximation in remote or limited accessibility applications.
Accordingly, it is an object of the present invention to provide apparatus for approximating jaw structure which provides accurate substantially parallel capture of subject tissue.
Another object of the present invention is to provide apparatus for approximating jaw structure for surgical instrumentation which permits parallel approximation of jaw structure on subject tissue in remote or limited accessibility conditions.
Other and further objects of the present invention will be explained hereinafter, and will be more particularly delineated in the appended claims, and other objects of the present invention will hereinafter become apparent to one with ordinary skill in the art to which the present invention pertains.